There is nothing worse than being halfway through a cut, a drill, or a drive, and your Makita 18V LXT tool suddenly loses power. We’ve all been there. BattAussie experts have been speak to hundreds of contractors who try to squeeze every last second out of an old pack, only to lose valuable billable hours.
The Makita BL1850B is a workhorse, but like all lithium-ion batteries, it isn’t immortal. How do you know if it’s time to retire the old pack and grab a fresh one? Here are the definitive signs your battery needs replacement, based on years of power tool experience.
1. The “Flash Light” Dance
If you press the charge button and see the LEDs flashing rapidly or blinking in a specific error pattern, your Makita tool battery is communicating a critical failure. While this can sometimes mean the tool is overheating, consistent flashing usually indicates a dead cell or a communication error between the battery and the charger.
2. Significant Runtime Drop
The BL1850B is rated for 5.0Ah. If you’ve noticed it now dies in half the time it used to—even after a full charge—the internal cells have likely reached the end of their cycle life. This “voltage sag” under load is a chemical reality; the battery simply can’t hold the charge anymore.
3. Physical Swelling
Safety First! If the plastic casing looks warped or “puffed,” remove the battery from your tool immediately. Swelling indicates gas buildup inside the cells, which is a serious fire hazard. Do not attempt to charge a swollen battery.
4. It Won’t Hold a Charge
You plug it in, the charger turns green immediately, but the tool dies after two minutes of use. This “phantom charging” means the battery management system (BMS) has lost calibration, or the cells are completely degraded.
5. Age (The 3-Year Rule)
Even if you don’t use it often, lithium-ion batteries degrade with time. If your Makita BL1850B tool battery is over 3 years old and showing any of the above signs, replacement is more cost-effective than repair.
Don’t let a dead battery slow down your crew. While genuine Makita batteries are great, Aussiebatt offers premium, high capacity replacement batteries that are rigorously tested for Australian conditions. We stock batteries with local warranties, ensuring you get the power of BL1850B without premium price tag.